Method of producing multicolored yarn



Dec. 1, 1970 R. WHITAKER METHOD OF PRODUCING MULTICOLORED YARN 2 Sheets-Sheet 1 Filed Aug. 25, 1967 INVIZNIOR RALPH WHITAKER F K H? ATTORNEYS.

Dec. 1, 1970 R. WHITAKER METHOD OF PRODUCING MULTICOLORED YARN 2 Sheets-Sheet 2 Filed Aug. 25, 1967 INVENIUR. RALPH WHITAKER WW! PW ATTORNEYS.

United States Patent 3,543,359 METHOD OF PRODUCING MULTICOLORED ARN US. Cl. 28-7216 6 Claims ABSTRACT OF THE DISCLOSURE Undrawn nylon yarn is knitted into a fabric and dye is applied to the fabric in spaced areas. The dye is heat set and the fabric is then deknitted. The resulting randomly dyed undrawn yarn is then drawn with a ratio of about 4 to 1. The resulting drawn yarn may 'be crimped.

BACKGROUND OF THE INVENTION This invention relates to the dyeing of yarns, and more particularly, to the dyeing of filaments which have been synthetically manufactured and extruded through openings such as those in a spinnerette, but prior to the time that the yarn is drawn.

In accordance with the prior art, and more specifically as shown in US. Pat. No. 3,012,303, issued Dec. 12, 1961 to R. Whitaker et al., and US. Pat. No. 3,102,322, issued Sept. 3, 1963 to R. Whitaker, yarns made of con tinuous filament thermoplastic synthetic fibers, such as nylon, were knitted into a prefabric and then the prefabric was dyed with localized areas of color and the dye was subsequently heat-set. The prefabric was then deknitted and the yarn was collected for further processing. This method was used in order to achieve a random dispersion of color in the final fabric.

The synthetic filaments used in the prior art processes to form the yarns, were first drawn to achieve desirable physical properties, such as surface texture and strength. For example, in the manufacture of nylon, it is usual to form the nylon in a bath by mixing chemicals together, and the resulting organic polymer is extruded through a spinnerette. Next, the extruded nylon is stretched on a draw frame, and this stretching is continued until the nylon is three or four times its original length. This stretching or drawing as it is known, orients the molecules in the polymer and aligns them in such a manner as to impart strength to the filament. The surface properties of the filament are changed by the drawing, in that the rough open areas on the undrawn filaments are closed up to a smooth surface.

Normally, the dye is either added in the initial bath or is applied to nylon after it has been drawn. To achieve lofty characteristics, the yarn is crimped by a variety of methods for crimping which are well known in the art.

In the processes described in the aforementioned patents, dye was applied to the filaments in localized areas of color subsequent to the drawing operation. As a result, the dye did not fully penetrate the filaments. I have now discovered and disclose in this application, a new method of dyeing synthetic filaments in localized areas of color which permits dyeing through the entire filament, rather than surface dyeing as in the prior art.

Furthermore, by changing the physical properties of the filaments which make up the yarn subsequent to the dyeing of the yarn, I am able to produce a unique multicolored yarn.

SUMMARY OF THE INVENTION The invention covers a new method of treating yarn and a new product produced by said method. The method comprises the steps of dyeing a yarn composed of undrawn synthetic filaments with one or more colors applied to localized areas of the yarn spaced apart from one another, and then drawing the yarn.

In the preferred embodiment of this invention, the undrawn synthetic filament yarn is first knitted into a prefabric, and then the prefabric is dyed with a multiplicity of colors which are applied in localized spaced-apart areas. The dye is then heat-set by passing the prefabric through a dye setting chamber. After this the prefabric is deknitted and the yarn is drawn.

The drawn yarn may be crimped prior to being formed into the final fabric to provide an unusual effect in the final form.

Accordingly, an object of this invention is to provide a new process for the production of intermittently colored yarn.

Another object of this invention is to provide a new process for the printing of yarn in intermittently colored areas wherein full penetration of the dye through the filament is achieved.

Another object of this invention is to provide a new process for producing a yarn having a multiplicity of colors wherein the boundaries between the colors are softened.

Another object of this invention is to provide new products for the textile industry, comprising intermittently colored and multicolored yarns having faster color chaarcteristics than have heretofore been known in the industry.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a spinnerette showing synthetic filaments being ejected therefrom;

FIG. 2 is a perspective view of a bundle of undrawn synthetic filaments forming a yarn;

FIG. 3 is a face view of a knitted flat prefabric illustrating a knitting step employed in the present invention;

FIG. 4 is a fragmentary perspective view showing the printing of stripes or other localized areas of color on the prefabric in the present invention;

FIG. 5 is a perspective view illustrating the raveling of the prefabric;

FIG. 6 is a diagrammatic central vertical section of a continuous heat-setting and dye-setting vessel used in the present invention;

FIG. 7 is a diagrammatic representation of a draw frame;

FIG. 8 shows a cross section of a synthetic filament which has been drawn and then dyed;

FIG. 9 shows a cross section of a synthetic filament which has been dyed before being drawn;

FIG. 10 is a diagrammatic view of a crimping apparatus;

FIG. 11 is a perspective view of a yarn composed of drawn synthetic filaments, which yarn has been dyed in localized areas subsequent to the drawing of the filaments;

FIG. 12 is a perspective view of a yarn composed of drawn synthetic filaments, which yarn had been dyed in localized areas prior to being drawn; and

FIG. 13 is a perspective view showing the effects of crimping on the yarn in FIG. 12.

DESCRIPTION OF THE PREFERRED EMBODIMENT Although specific forms of the invention have been selected for illustration in the drawings, and the following description is drawn in specific terms with the purpose of describing those forms of the invention, this description is not intended to limit the scope of the invention.

Referring to the drawings, FIG. 1 shows synthetic continuous filaments 21 being formed as they issue from a spinnerette 22 as part of the conventional nylon producing process which is well known in the art. These synthetic filaments are shown in FIG. 2 forming a yarn 23. Filaments for use in this invention are considered to be of a continuous filament thermoplastic synthetic type, such as nylon, Orlon, etc.

In the prior art, it is usual at this stage to draw the undrawn synthetic yarn on a draw frame to several times its length. In this condition it is then subjected to other operations, such as dyeing, crimping, etc. However, according to this invention, the undrawn synthetic yarn is knitted and dyed prior to being drawn. The advantages of this invention will become evident from the description which follows.

As disclosed in FIG. 3, the yarn 23 is first knitted into a prefabric 24 having crimps or loops 25. The knitting may be conducted on a flat or circular knitting machine to produce the prefabric. The advantages of this invention can be achieved whether the prefabric is fiat or ribbed.

After the prefabric is knitted, stripes or other localized areas of one or more colors are applied across the prefabric, preferably at an angle to the direction in which the yarn extends, all as disclosed in my prior Pat. Nos. 3,012,303 and 3,102,322. FIG. 4 shows prefabric 24 moving in the direction of the arrow, through a plurality of printing or padding stations 27 and 28, each applying a different color. The individual dyed areas may or may not be adjoining; if desired natural intervening areas may be left unprinted. While stripes have been shown as being printed or padded, it will be evident that the color can be applied by other means within the scope of my invention, so long as these means apply the colors intermittently. Colors may be applied to one or both sides of the prefabric.

The knitted prefabric, preferably after the application of localized areas of color, is next heat-set. For this purpose the prefabric 24 is conveniently placed in a chamber 32, as shown in FIG. 6. In this case, the prefabric passes through the chamber on driven rolls 33; steam is admitted through the pipes 34 to maintain a preferred temperature of ISO-270 F., most preferably about 210215 F.

While it is preferred to apply the localized areas of the color prior to heat-setting, it will be evident that if it is desired the color can be applied independently of the heat-setting, and that in any case, the dye of the localized areas can be fixed by any suitable means if required.

After completion of the heat-setting and the normal scouring and drying, the prefabric 24 is raveled or deknitted, as shown at 37, FIG. 5.

The deknitted yarn 38 is next drawn on a draw frame 39, FIG. 7 preferably to approximately three to four times its original length. Drawing gives the yarn desirable physical properties for use in other textile operations, and ultimately, for use in the making of the final fabric. The drawing of the nylon to at least approximately three times its original length orients the molecules in the polymer and operates to remove the crimp which was imparted to the undrawn yarn by the incorporation of the yarn into the fabric and the application and heat setting of the dye in the yarn.

One such operation is crimping, which is shown diagrammatically in FIG. 10. The drawn yarn 40 is fed through crimping rollers 41 and 42 into a stuffer box 43 where it is crimped under pressure by an apparatus well known in the art.

The process described produces a new product having distinctive color characteristics. The undrawn yarn itself is much more receptive to receiving dye than is drawn yarn. FIG. 8 shows a cross section of a filament of drawn synthetic yarn which has been dyed subsequent to drawing. The filament 45 has been only partially penetrated by the dye, as shown by the darker area 46. In compari- 4 son, the undrawn filament 47 shown in FIG. 9 has been dyed in the undrawn state. The cross section reveals that penetration of the dye is substantially complete, as at 48. In comparing these figures, it should be assumed that they represent the same type of synthetic fiber and that they were dyed together by the same means.

It should be apparent from FIGS. 8 and 9 that undrawn yarn is more receptive to color, and that penetration of the dye is greater when imprinting undrawn yarn than drawn yarn. Another advantage of dyeing the yarn prior to drawing it, is that the colors are faster because the printing paste penetrates the many open dye sites or rough spots on the surface of the undrawn filament, which sites are eliminated or closed up by drawing. For example, in the printing of undrawn filament of about 60 denier there is a much larger surface area and hence more printing area for the colors to lodge, than there would be after the yarn filaments have been drawn down to about 15 denier. In the process of the drawing, the dye lodging in the crevices is more or less entrapped. The effect of this characteristic will become more apparent from a discussion of FIGS. 11 and 12.

FIG. 11 shows a piece of drawn yarn 70 in perspective. The yarn 70 has been dyed in localized areas subsequent to being drawn. As clearly shown, the drawn yarn 70 has regular and distinctly defined color areas thereon, such as at 35 and 36. The boundary 50 between these color areas is sharply defined. If a cross section were taken through one of these color areas and the filament were examined closely, it would appear similar to the filament in FIG. 8, wherein the filament has been only partially penetrated by the dye.

FIG. 12 shows the appearance of a yarn which has been treated in accordance with my invention. The resultant yarn 40 has elongated color areas 35a and 36a. These color areas resulted from the stretching of the yarn. If a cross section were to be taken through one of these color areas and a single filament examined closely, it would appear to be similar to the filament 47 shown in FIG. 9, wherein the dye has penetrated through the entire filament, rather than the mere surface dyeing shown in FIG. 8.

As a by-product of the process just described, note that the color at the boundary a is much less definite and distinct than the color at the boundary 50 of the yarn 70 in FIG. 11.

In addition, the filaments forming the yarn 40 have been elongated more in some areas than in others, so that a random orientation exists between the color areas on the filaments. Also the elongation produces a lightening of the colors in that the intensity of the dye diminishes gradually toward the edges of each dyed area. The blending of the colors at the boundary areas, the random orientation, and the lightening combine to produce a softer visual effect.

If the yarn is crimped subsequent to drawing, a still further color orientation is achieved, as shown in FIG. 13. Here the crimping has produced a further change in the visual effect, in that the crimps in the yarn are not disposed at the same color boundary for each piece of synthetic filament in the yarn.

It will be apparent that changes can be made to various steps in this method within the scope of the invention.

It will be understood that various changes in the details, materials and arrangement of parts which have been herein described and illustrated in order to explain the nature of this invention, may be made by those skilled in the art within the principle and scope of the invention.

What is claimed is:

1. In the method of producing a yarn having random intermittent coloring in spaced-apart zones throughout its length, wherein yarn is supplied and colored by incorporating the yarn into a prefabric and coloring the prefabric by applying a dye thereto in spaced bands which run transversely to the direction of the yarn in the prefabric so as to impart coloring to the yarn in said spacedapart zones throughout the length thereof, heat-setting said prefabric and raveling said prefabric to produce at least one individual strand of heat-set yarn which is dyed in said spaced-apart zones intermittently along its length, the improved method of providing in the strand of intermittently dyed yarn a graduated intensity of the dye toward the edges of each dyed zone comprising supplying a multifilament undrawn synthetic yarn characterized by surface properties including rough open areas into which the dye may penetrate, and including the addi tional step of drawing said multifilament yarns to at least approximately three times its original length after the coloring step so as to elongate the filaments of the multi filament yarn, thereby removing the crimp imparted to said dyed yarns during the formation of and heat setting of the prefabric, and to effect a softening of the line of demarcation at the ends of said spaced-apart zones and a graduation in dye intensity at the ends of said zones as the individual filaments of the multifilament yarn are drawn out during the drawing process.

2. A method according to claim 1 including the step of texturizing the decrimped drawn yarn after raveling to impart bulk to the multifilament yarn, thereby further softening the line of demarcation at the ends of said spaced-apart zones.

3. A method according to claim 1 wherein said step of incorporating the yarn into a prefabric comprises knitting the undrawn yarn into a weft-knitted tubular prefabric, and said raveling step comprises deknitting the prefabric.

4. A method according to claim 1 wherein the heatsetting step fixes the dye by passing the prefabric through a steam-heated dye setting chamber prior to raveling.

5. A method according to claim 1 wherein said prefabric is formed in a predetermined width and of indeterminate length, said bands of dye being applied to the prefabric diagonally of its width and length.

6. A method according to claim 5 wherein said bands are applied in criss-cross fashion diagonally of the prefabric.

References Cited UNITED STATES PATENTS ROBERT R. MACKEY, Primary Examiner U.S. Cl. X.R. 2874, 

